I think that Nintendo could use some changes, but they would have to be slow and gradual. You can't just drop everything in the name of making creative and original games, for that would severely damage the company. I would provide the option of the classic/Gamecube controller for all future games too (except those casual, minigame collection things where the Wiimote is the key gimmick) as the Wii motion controls can be somewhat unresponsive at times. The Mario (that includes Wario and Yoshi series as well), Legend of Zelda, Metroid, and Pokemon series seem to be the crux of Nintendo's money making strategy, so I would have to keep making these for at least a while longer. Pikmin was thought to be a trilogy, so I can't leave that hanging. However, as time went on, I would try to draw focus away from these series and introduce some new ones. Like I said, it would have to be very gradual to avoid alienating the fan base. Anyway, here are my ideas for some of Nintendo's existing franchises:
As for Mario, I'd get him out of space as soon as possible. For Mario, I feel that going into space was the equivalent of waterskiing in shark infested waters, if you know what I mean. He could jump over one of them at any time! The Mushroom World needs some more consistency, as well. One more thing: a full 3D Mario RPG. Epic.
I don't have many ideas for Legend of Zelda; it seems to be doing its trick just fine. However, I've heard that it has a very distinct timeline known only to Nintendo, and they're working to reveal it all. I'd definately have to keep this series on board long enough to figure that mess out. We would definately have to mix things up, though. Twilight Princess seems way too familiar to me. I heard they did a hoax about a Legend of Zelda game set in a steampunk setting. I think we could fit that in somewhere, so long as it was the gorons who invented the steam tech (yay gorons!).
I'm not sure what to do with Metroid, but if we keep it around for much longer I will call for fleshing out the world of the series. I mean, it has all these races and cultures that just happen to all be extinct. I'd like to see some races and cultures that happen to still be alive. You can call me a heretic if you want, but I also think that Samus should have some more lines and characterization, but then again I think we might see some of that in Metroid: The Other M. If that's the case, I would consider that a huge plus.
I think the Pokemon series is doing its job just fine, and I think the standard RPG format it's been using is still good. However, I would very much like to "widen the focus" of the series, so to speak. I mean, Pokemon are cool and everything, but I'd like to see more of the world around them. I think the past couple of movies have been doing this pretty well, especially the one with Manaphy. I'd also want to make the criminal organizations like Team Rocket portrayed more seriously. One should be able to tell that the criminals are evil, evil people and are a serious threat (never played Gale of Darkness, but Cipher seems to be like this). Of course, that might be difficult to pull off and still maintain the E rating. As for the games themselves, I think we should try again with making a full 3D Pokemon game, but keep it in the same vein as the other games, with Gym Leaders and an Elite Four, and all that stuff. There should also be some sort of character creation, where you can select your characters gender as well as age, physical appearance, and apparel, rather than just being the same generic kid with a selected name.
One last thought, though. At the end of the day, the foundation of Nintendo's audience are the children, and I think the best way to bring them in is to have the characters and stories present in other media than the games themselves, and by that I mean bring back the Saturday morning cartoons. I think that television is a great way to bring in the children, as it gets them interested in the characters and stories without them having to devote any money to it, as cable is a given in pretty much any home. If they like the shows, then it stands to reason that they'll beg their parents for the games. However, this time around I think we should make them a little less campy in order to raise the top end of the target demographic up to the 13-14 range.